ERBB2 and cancer: These biomarkers include and are not limited to germline breast cancer gene 1/2(BRCA1/2) mutation (gBRCAm) in HER2-negative, programmed death-1 ligand (PD-L1) status in TNBC and phosphatidyl inositol-4,5-bisphosphonate 3-kinase catalytic sub-unit alpha (PIKA3CA) in ER/PR+ HER2-negative cancers [3].